The present invention relates to oral pharmaceutical compositions, in particular to compositions containing buprenorphin as active ingredient. These compositions are particularly stable with respect to the commercially available products.
Buprenorphin, namely 21-cyclopropyl-7xcex1-(2-hydroxy-3,3-dimethyl-2butyl-)-6,14-endo-ethano-6,7,8,18-tetrahydroripavine, is a morphine alkaloid with analgesic properties. Its preparation is disclosed in U.S. Pat. No. 3,433,791, for a review see J. W. Lewis in Advan. Biochem. Psychopharmacol. Vol. 8, M. C. Braude et al. eds. (Raven Press, New York, 1974).
This analgesic is marketed under the trade marks TEMGESIC, BUPRENEX, LEPETAN.
Sublingual tablets containing buprenorphin as active ingredient, for example TEMGESIC 0.2 and 0.4 mg, show the presence of products from the degradation of the active ingredient.
It has now been found that the addition of pharmaceutically acceptable antioxidants gives oral pharmaceutical compositions, containing buprenorphin or a pharmaceutically acceptable salt thereof as active ingredient, a particularly good stability, decreasing the formation of the degradation products.
Advantageously, the oral pharmaceutical compositions according to the present invention are more stable than the presently available dosage forms of the state of the art, hence they have a longer shell-life.
Therefore, it is an object of the present invention an oral pharmaceutical composition containing buprenorphin or a pharmaceutically acceptable salt thereof as active ingredient characterised in that it contains a pharmaceutically acceptable antioxidant in addition to conventional vehicles and eccipients.
This and other objects of the present invention will be disclosed in detail, also by means of examples.